A three-dimensional (3D) stereoscopic image display technology refers to a technology of reconstructing a two-dimensional (2D) image by adding predetermined depth information to the 2D image.
The 3D stereoscopic image display technology uses binocular disparity of human eyes to provide a 3D image. Methods for separating left and right images using the binocular disparity are classified into glasses type and glasses-free type. Examples of the glasses type method may include an anaglyph method, a polarized glasses method, and a shutter glasses method, and examples of the glasses-free type method may include a lenticular method, a parallax barrier method, and an optical plate method. Among these conventional methods, the polarized glasses method and the shutter glasses method are the oldest 3D display methods and have been widely used in 3D movies and 3D TVs. However, the polarized glasses method and the shutter glasses method require wearing special glasses for stereoscopic images and increase eye strain. Among the glasses-free type methods, the lenticular method and the parallax barrier method fix an observer's observation points to low-brightness and low-resolution images and cause headaches or dizziness when the observer constantly watches the images.
Meanwhile, examples of a complete stereoscopic method include a hologram method and a volumetric 3D display method. These complete stereoscopic methods implement only static stereoscopic images through a high-priced laser and precision optical apparatus but cannot provide real-time high-quality stereoscopic images.
Recently, methods for implementing real-time stereoscopic images at low costs by using a half mirror, a concave mirror, a Fresnel lens, a prism array, and the like have been suggested. However, the method using a half mirror reflects an image as a virtual image and requires a large physical size of the system, and the methods using a concave mirror, a Fresnel lens, and a prism array require high manufacturing costs and provide a narrow viewing angle. Particularly, in the case where a stereoscopic image is implemented using a prism array, the image quality may deteriorate.